Integrated fuel injector igniters with conductive cable assemblies

ABSTRACT

The present disclosure is directed to a fuel injector assembly including a valve and a cable assembly for actuating the valve. The cable can include a plurality of strands, and each strand can be an optical fiber, an electrical conductor, or a tensile member capable of withstanding a tensile stress caused when the valve actuator actuates the valve, or any combination thereof. The cable can also include a brush bearing with bristles extending from the cable to maintain the cable at least generally centered within a channel as the cable moves in the channel. The bristles can be electrically conductive and can convey a voltage to an electrode pair near the valve to ionize at least a portion of the fuel to urge the fuel from the injector through the valve.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 12/841,146, filed Jul. 21, 2010 and titled INTEGRATED FUELINJECTOR IGNITERS WITH CONDUCTIVE CABLE ASSEMBLIES which is acontinuation-in-part of U.S. patent application Ser. No. 12/653,085,filed Dec. 7, 2009 (now U.S. Pat. No. 7,628,137 which issued Dec. 8,2009) titled INTEGRATED FUEL INJECTORS AND IGNITERS AND ASSOCIATEDMETHODS OF USE AND MANUFACTURE which claims benefit of priority to U.S.Provisional Application No. 61/237,466, filed Aug. 27, 2009 titledMULTIFUEL MULTIBURST. U.S. patent application Ser. No. 12/841,146 is acontinuation-in-part of U.S. patent application Ser. No. 12/581,825,filed Oct. 19, 2009 (now U.S. Pat. No. 8,297,254 issued Oct. 30, 2012)titled MULTIFUEL STORAGE, METERING AND IGNITION SYSTEM which is adivisional of U.S. patent application Ser. No. 12/006,774, filed Jan. 7,2008 (now U.S. Pat. No. 7,628,137 which issued Dec. 8, 2009) titledMULTIFUEL STORAGE, METERING AND IGNITION SYSTEM. U.S. patent applicationSer. No. 12/841,146 claims benefit of priority to U.S. ProvisionalApplication No. 61/237,425, filed Aug. 29, 2009 titled OXYGENATED FUELPRODUCTION; U.S. Provisional Application No. 61/237,479, filed Aug. 27,2009 titled FUEL SPECTRUM ENERGY; U.S. Provisional Application No.61/304,403, filed Feb. 13, 2010 titled FULL SPECTRUM ENERGY AND RESOURCEINDEPENDENCE; U.S. Provisional Application No. 61/312,100, filed Mar. 9,2010 titled SYSTEM AND METHOD FOR PROVIDING HIGH VOLTAGE RF SHIELDING,FOR EXAMPLE, FOR USE WITH A FUEL INJECTOR; and is a continuation-in-partof PCT/US2009/067044, filed Dec. 7, 2009 titled INTEGRATED FUELINJECTORS AND IGNITERS AND ASSOCIATED METHODS OF USE AND MANUFACTURE.Each of these applications is incorporated herein by reference in theirentirety. To the extent the foregoing application and/or any othermaterials incorporated herein by reference conflict with the disclosurepresented herein, the disclosure herein controls.

TECHNICAL FIELD

The following disclosure relates generally to fiber optic and/orconductive cable assemblies and centering brush bearings and associatedcomponents for operating a fuel injection valve.

BACKGROUND

Fuel injectors are used to inject fuel into a combustion chamber of acombustion engine. The fuel is generally pressurized and released intothe combustion chamber at a specific time relative to a stroke of theengine when a valve is opened between a chamber containing thepressurized fuel and the combustion chamber. Recent advances in controltechnology have allowed great efficiency and power production gains frommonitoring a combustion event, such as temperature, light, pressure, ormovement within the combustion chamber. However, conventional fuelinjection valves and combustion chambers are not equipped to monitor thecombustion events, and in many existing engines can not easily beadapted for use with monitoring equipment. In many fuel injectorconfigurations, the size of the bore through which the fuel injectorenters the combustion chamber is small and limits the type of equipmentthat can be used to monitor the combustion event. Accordingly, thereexists a need for an improved way to deliver fuel to a combustionchamber and to measure a combustion event within the chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional side view of a fuel injector inaccordance with an embodiment of the disclosure.

FIG. 2A is an isometric view of a cable according to embodiments of thedisclosure.

FIG. 2B is a cross-sectional view of the cable of FIG. 2A according toembodiments of the disclosure.

FIG. 2C is a cross-sectional view of the cable of FIG. 2A according toembodiments of the disclosure.

FIG. 3A is an isometric view of a cable according to embodiments of thedisclosure.

FIG. 3B is a cross-sectional view of the cable of FIG. 3A according toembodiments of the disclosure.

FIG. 4A is an isometric view of a cable according to embodiments of thedisclosure.

FIG. 4B is a cross-sectional view of the cable of FIG. 4A according toembodiments of the disclosure.

FIG. 5 is a cross sectional view of a cable according to embodiments ofthe disclosure.

FIG. 6 is a cross sectional view of a cable according to embodiments ofthe disclosure.

FIG. 7 is a cross-sectional view of a cable according to embodiments ofthe disclosure.

FIG. 8A is a length-wise cross-sectional view of a cable having a stopaccording to embodiments of the disclosure.

FIG. 8B is a width-wise cross-sectional view of the cable of FIG. 8Aaccording to embodiments of the disclosure.

FIG. 8C is a width-wise cross-sectional view of the cable of FIG. 8Aaccording to embodiments of the disclosure.

DETAILED DESCRIPTION

The present application incorporates by reference in their entirety thesubject matter of each of the following U.S. patent applications, filedconcurrently herewith on Jul. 21, 2010 and titled: INTEGRATED FUELINJECTORS AND IGNITERS AND ASSOCIATED METHODS OF USE AND MANUFACTURE(Attorney Docket No. 69545-8031US); FUEL INJECTOR ACTUATOR ASSEMBLIESAND ASSOCIATED METHODS OF USE AND MANUFACTURE (Attorney Docket No.69545-8032US); SHAPING A FUEL CHARGE IN A COMBUSTION CHAMBER WITHMULTIPLE DRIVERS AND/OR IONIZATION CONTROL (Attorney Docket No.69545-8034US); CERAMIC INSULATOR AND METHODS OF USE AND MANUFACTURETHEREOF (Attorney Docket No. 69545-8036US); METHOD AND SYSTEM OFTHERMOCHEMICAL REGENERATION TO PROVIDE OXYGENATED FUEL, FOR EXAMPLE,WITH FUEL-COOLED FUEL INJECTORS (Attorney Docket No. 69545-8037US); andMETHODS AND SYSTEMS FOR REDUCING THE FORMATION OF OXIDES OF NITROGENDURING COMBUSTION IN ENGINES (Attorney Docket No. 69545-8038US).

The present disclosure describes devices, systems, and methods forproviding a fuel injector assembly including a fiber optic and/orelectrically conductive cable and optical combustion measuring unit. Thedisclosure further describes a bearing comprising generally rigidbristles extending from the cable to maintain the cable within a channelof a fuel injector, as well as associated systems, assemblies,components, and methods. Certain details are set forth in the followingdescription and in FIGS. 1-8C to provide a thorough understanding ofvarious embodiments of the disclosure. However, other details describingwell-known structures and systems often associated with internalcombustion engines, injectors, igniters, and/or other aspects ofcombustion systems are not set forth below to avoid unnecessarilyobscuring the description of various embodiments of the disclosure.Thus, it will be appreciated that several of the details set forth beloware provided to describe the following embodiments in a mannersufficient to enable a person skilled in the relevant art to make anduse the disclosed embodiments. Several of the details and advantagesdescribed below, however, may not be necessary to practice certainembodiments of the disclosure.

Many of the details, dimensions, angles, shapes, and other featuresshown in the Figures are merely illustrative of particular embodimentsof the disclosure. Accordingly, other embodiments can have otherdetails, dimensions, angles, and features without departing from thespirit or scope of the present disclosure. In addition, those ofordinary skill in the art will appreciate that further embodiments ofthe disclosure can be practiced without several of the details describedbelow.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the present disclosure. Thus, theoccurrences of the phrases “in one embodiment” or “in an embodiment” invarious places throughout this specification are not necessarily allreferring to the same embodiment. Furthermore, the particular features,structures, or characteristics may be combined in any suitable manner inone or more embodiments. The headings provided herein are forconvenience only and do not interpret the scope or meaning of theclaimed disclosure.

FIG. 1 is a schematic cross-sectional side view of a fuel injectorassembly 100 in accordance with several embodiments of the presentdisclosure. The assembly 100 includes a dielectric body 110 having achannel 114 extending longitudinally through the body 110. The channel114 extends between a fuel combustion chamber 116 and a fuel reservoir118 to carry fuel from the fuel reservoir 118 along the channel 114 andinto the combustion chamber 116. The fuel injector assembly 100 can alsoinclude a housing 112 surrounding the body 110. The housing 112 can bean electro-magnetic shield or a mechanical reinforcement to strengthenthe assembly 100. The housing 112 is optional, and can be included inapplications where the additional strength and/or electrical shieldingare advantageous. The assembly 100 can further include an electricallyconductive cable assembly 120 contained in the channel 114 that caninclude a cable body 121 with a valve 122 at an end of the cable body121 positioned between the channel 114 and the fuel combustion chamber116. The assembly 100 can also include a valve actuator 124, such as asolenoid, a spring, or other actuator, that is connected to the cablebody 121 and moves the valve 122 back and forth to actuate the valve 122to inject fuel into the combustion chamber 116. The valve 112 caninclude a sensor 126, such as an optical head, that can detect acombustion event in the fuel combustion chamber 116 by detecting atleast one of temperature, light, pressure, sound, or motion within thecombustion chamber. The cable 120 can relay a signal representing thecombustion event through the cable body 121.

The combustion chamber 116 contains a piston (not shown) that is drivenby timed bursts of combusted fuel in the combustion chamber 116. Thefuel injector assembly 100 is configured to deliver precisely timedquantities of fuel into the combustion chamber to mix with oxygen in thechamber. The piston can pressurize the fuel-oxygen mixture, and asparkplug (or equivalent) ignites the fuel in the combustion chamber 116to move the piston, which delivers power to a crankshaft (not shown). Toassist fuel delivery, the assembly 100 can create a plasma by ionizing aportion of the fuel to force the fuel into the combustion chamber 116quickly and efficiently. To create the plasma, an electrical current canbe delivered from an ionizing power source 130 to electrodes in thechannel 114. In some embodiments, the valve 122 and an engine section131 near the valve 122 can operate as the electrodes. Further details offuel injectors, combustion chambers, and related devices, techniques,and methods are given in U.S. patent application Ser. No. 12/653,085,which is incorporated herein by reference in its entirety.

FIGS. 2A-7 illustrate various isometric and cross-sectional views of thecable body 121 according to several embodiments of the presentdisclosure. FIG. 2A shows an isometric view of a cable 200 a, and FIGS.2B and 2C show cross-sectional views of the cable 200 a. FIG. 2B shows asingle stem tube 210, including a fiber optic component 202, a cladding204, and a sheath 206. The fiber optic component 202 can includemultiple fiber optic cores, and can be arranged off-center relative tothe stem tube 210 in various arrangements. The fiber optic component 202can be made of any material that perpetuates an optical signal, such assilica, fluorozirconate, fluoroaluminate, chalcogenide glass, sapphire,or phosphate glass. The fiber optic component 202 can be adapted totransmit optical signals of different wavelengths and types. Also, thecladding 204 can be made of different materials and in variouscombinations with materials of the fiber optic core 202. The sheath 206can be electrically conductive or electrically non-conductive, and canbe load-bearing. In some embodiments, the sheath 206 can be omitted, andthe fiber optic component 202 can be made of a relatively strongmaterial such as fiber glass, polyimide, polyamide-imide, aluminumfluoride, quartz, and sapphire, and configured to withstand tensileforces caused in the stem tube 210 as the valve 122 is actuated.

The cable 200 a can have multiple stem tubes 210, as shown in FIG. 2C,extending along the cable 200 a. An encasement 212 made of a plastic orother insulating material can surround the stem tubes 210 to protect thestem tubes 210 from the fuel flowing through the channel 114 (FIG. 1) orany other environmental hazard that may damage the stem tubes 210. Theencasement 212 can surround any group of the stem tubes 210, including asingle stem tube 210. The encasement 212 is optional and can be omitted.In some embodiments, the cable 200 a includes a brush bearing 214 havingbristles 214 a extending between the stem tubes 210 and extendingradially from a central point 201 of the cable 200 a. In someembodiments, the stem tubes 210 are twisted in a helical configuration,and therefore the bristles 214 a can also form a helix around the centerpoint 201. The brush bearing 214 can maintain the cable 200 a at leastgenerally centered within the channel 114 as the cable 200 a is vibratedor moved longitudinally to actuate a valve or other device. The brushbearing 214 can provide a unidirectional bearing that maintains motionof the valve 122 (FIG. 1) on a centerline of the channel 114 (FIG. 1).The bearing 214 can also provide protection for the stem tubes in thechannel 114. The bristles 214 a can be made of carbon and/or copperfilled carbon brushes similar to those utilized against the rotors ofmotors and generators.

The stem tubes 210 can be an electrically conductive optical strand thatcan withstand a tensile load caused when the cable 200 a is used toactuate a valve or other device. For example, the stem tubes 210 can bemade of a material, such as an aluminum fluoride, that operates as anoptical waveguide, is electrically conductive, and has sufficienttensile strength to be used to actuate a fuel injection valve or otherdevice. The cable 200 a can accordingly be used to carry an opticalsignal from the sensor 126, to carry a voltage to the electrodes tocause the plasma in the fuel, and to actuate the valve 122. The voltagecan be a DC voltage, or an AC voltage at an appropriate frequency,including a high-frequency. In some embodiments, the stem tubes 210 canhave different combinations of these characteristics. For example, thecable 200 a can include a first stem tube 210 a that includes opticalfibers for carrying an optical signal, and a second stem tube 210 b thatis a tensile member. Either of the first or second stem tubes 210 a, 210b can also be electrically conductive in order to carry a voltage to anelectrode pair to ionize a portion of the fuel. In some embodiments, thestem tubes 210 are both made of optical fibers having sufficientstrength to withstand a tensile load caused by actuating the valve 122.

Twisting or braiding the conductive cable assembly diffuses the voltageacross the cross-sectional area of the cable assembly and reducesproblems associated with a phenomenon known as the “skin effect.” Athigh-frequency, the electrical signal in a conductor tends to be carriedprimarily at the outermost portion, or skin, of the conductor. Thisphenomenon causes increased resistance because it reduces the effectivecross-sectional area of the conductor, which is inversely related to theresistance of the conductor. The skin effect can be overcome by braidingor otherwise weaving wires in a litz array such that each wire in anarray of wires alternates between the outside and inside of the wire atdifferent portions of the wire. Generally, each wire is electricallyisolated from the rest to prevent the wires from shorting together intoa composite wire which also experiences the skin effect.

FIG. 3A illustrates an isometric view of another cable 200 b, and FIG.3B depicts a cross-sectional view of the cable 200 b according toseveral embodiments of the present disclosure. The cable 200 b caninclude four stem tubes 210 and a brush bearing 214 similar to the cable200 a shown in FIGS. 2A-2C. The brush bearing 214 can include a firstsection of bristles 214 a and a second section of bristles 214 bextending between the stem tubes 210 at an angle relative to the firstsection of bristles 214 a. The strands can be wound, causing the twobristle sections to form a double-helix about a center point 201 shownin FIG. 3B. The first bristles 214 a and second bristles 214 b can bemade of the same material, or different materials.

In some embodiments, a first stem tube 210 a can be an opticalwaveguide, a second stem tube 210 b can be electrically conductive, anda third stem tube 210 c can be a tensile member capable of withstandinga tensile load caused when the valve actuator 124 pulls on the cable 200b. Accordingly, the optical signal from the sensor 126 can be carried bythe first stem tube 210 a, the electricity for creating the plasma canbe carried by the second stem tube 210 b, and the tensile load can becarried by the third stem tube 210 c. A fourth stem tube 210 d can be anoptical fiber, an electrical conductor, or a tensile member, or have anycombination of these characteristics. In some embodiments, the stemtubes 210 can all have different combinations of these characteristics,as needed by a particular application, and according to designpreferences. For example, a material with the optical, electrical, andmechanical properties may allow the cable 200 b to have a smallerdiameter, but may be more expensive than a material having only one ortwo of these properties but may increase the diameter of the cable 200b. Although the stem tubes 210 are shown here having a similar diameter,a given application may call for different stem tubes 210 to havedifferent diameters.

FIGS. 4A, 4B, and 5 show cables 200 c and 200 d, respectively, havingalternative arrangements. Cables 200 c and 200 d include a central stemtube 210 e and several peripheral stem tubes 210 f. Many features ofthese cables 200 c and 200 d are generally similar to features of thecables 200 a and 200 b discussed above in FIGS. 2A-3B including a brushbearing 214. It is to be understood that various other configurationsare possible, including various numbers and arrangements of the stemtubes 210 and bristles.

FIG. 6 shows another cable 200 e in which a first group of stem tubes210 g have a first diameter, and a second group of stem tubes 210 h havea second, larger diameter. The cable 200 e can include a firstencasement 212 a around the first group of stem tubes 210 g and a secondencasement 212 b around the second group of stem tubes 210 h. In someembodiments, the cable 200 e does not include an encasement 212. Due totheir larger size, the second group of stem tubes 210 h can be tensilemembers, and the first group of stem tubes 210 g can be the opticaland/or electrical strands. In any configuration shown herein thatincludes at least one electrically conductive strand, the stem tubes 210can be arranged in a litz array to mitigate the skin effect discussedabove. The size, shape, and number of stem tubes 210 depends on manyvariables, and this disclosure is not limited to a specific arrangementor number of strands.

FIG. 7 shows yet anther cable 200 f including three groups of stem tubes210. The cable 200 f includes a first group 220 of stem tubes 210, asecond group 222 of stem tubes 210 wound at least generallyconcentrically around the first group 220, and a third group 224 woundat least generally concentrically around the second group 222. In someembodiments, stem tubes 210 in the first group 220 contains opticalfibers, stem tubes 210 in the second group 222 are electricallyconductive, and stem tubes 210 in the third group 224 includes tensilemembers. The groups can be mechanically insulated such that a tensileforce carried by the tensile members in the third group 224 does nottranslate to stem tubes 210 in the second group 222 or the first group220. Similarly, stem tubes 210 in one group can be electrically and/oroptically insulated from stem tubes 210 in other groups. In otherembodiments, the third group can be omitted because the tensile load iscarried by stem tubes 210 in the first group 220 or in the second group222. Each group can include a plurality of stem tubes 210, which can bebraided or woven in a litz array to mitigate the skin effect in thecable 200 f. In some embodiments, the electrically conductive portionsof cable 200 f are used to transmit a DC voltage. Accordingly, a singlestem tube 210 can be used, or the stem tubes 210 can be unbraided,because the skin effect generally is not present with a DC voltage. Theembodiments shown in FIG. 7 may include bristles (not shown) similar toembodiments shown and described above with reference to FIGS. 2-6.

Referring back to FIG. 1, the channel 114 can include an electricallyconductive sleeve 132 connected to a power source 130 through a wire133. The sleeve 132 can be stationary relative to the body 110 while thecable body 121 moves back and forth in the channel 114 as the valve 122is actuated. A first portion of the bristles 123 a can be electricallyconductive to form an electrical path between the power source 130 andthe electrodes 122, 131. The conductive bristles 123 a can overlap withthe sleeve 132 sufficiently that the bristles 123 a contact the sleeve132 through the stroke of the cable body 121 from the closed position tothe open position. The voltage can be applied through the bristles 123 aand can be further carried by the cable body 121 between the conductivebristles 123 a and the valve 122. In some embodiments, a second portionof the bristles 123 b that does not contact the sleeve 132 is notnecessarily part of the electrical path between the valve 112 and theionizing power source 130. Accordingly, the bristles 123 b can be chosenof a material to reduce friction and not necessarily for theirelectrical properties. For example, the bristles 123 b can be made of anon-conductive nylon or a polyamide-imide. To mitigate wear in thechannel 114, the channel 114 can be lined with a plating or liner madeof an alloy similar to the material disclosed in U.S. Pat. No.4,742,265, which is incorporated herein by reference. This arrangementallows the wire 133 to remain stationary while the cable 120 moves toavoid fatigue in the wire 133. Also, the stroke of the cable 120 betweenopen and closed can be much larger than other designs because the wire133 does not experience fatigue caused by moving with the wire 133. Alarger stroke allows the assembly 100 to be used in large engines thatcall for a relatively large quantity of fuel to be injected into thecombustion chamber 116, such as large ships and construction equipment,etc.

FIGS. 8A-8C illustrate other embodiments of the present disclosure. FIG.8A shows a cross-sectional view of a cable assembly 300 and an actuator302. The cable assembly 300 includes a center cable section 310, a stop320 around a portion of the center cable section 310, and an outer cablesection 330 layered at least generally concentrically with the stop 320and the center cable section 310. The cable assembly 300 is situatedwithin the actuator 302 which actuates the cable assembly 300. Theactuator 302 can include a solenoid, a magnet, a spring, or any otherequivalent device to actuate the cable assembly 300. The actuator 302can be generally similar to the actuator 124 shown in FIG. 1. Theactuator 302 can include a shoulder 304 against which the cable assembly300 abuts to limit the range of motion of the cable assembly 300relative to the actuator 302. The shoulder 304 can be sloped to at leastgenerally match a slope of the stop 320 to provide a large contact areato distribute pressure caused when the actuator 302 pulls the cableassembly 300 into the actuator 302. In some embodiments, the shoulder304 is not part of the physical housing of the actuator 302, and is aseparate piece, such as a collar, that has sufficient rigidity towithstand the actuating force from the actuator 302. Limiting the motionof the cable assembly 300, and a valve (or other equipment) at an end ofthe cable assembly 300, allows for the valve to be opened a precise,consistent distance each time the cable assembly 300 is actuated.

The stop 320 can be fixed to the central cable section 310, and caninclude barbs 322 on an outer surface contacting the outer cable section330. The barbs 322 fix the outer cable section 330 to the stop 320 sothat when the actuator 302 actuates the cable assembly 300, the stop 320abuts the shoulder 304 and stops the cable assembly 300 from movingrelative to the shoulder 304. In some embodiments, the barbs 322 aredirectional. For example, as shown in FIG. 8A, the barbs 322 aredirected away from the actuator 302. In other embodiments the barbs 322are not directional. The stop 320 can include an adhesive or othertechniques to prevent the stop 320 from moving relative to the centralcable section 310 and the outer cable section 330. The stop 320 can bemade of a dielectric material, or an electrically conductive material.The stop 320 can be at least generally rigid and withstand thecompressive forces caused by the actuator 302 when the stop 320 ispressed against the shoulder 304. The stop 320 also adds sectionstiffness to the able assembly. Accordingly, the inner and outer cablesections 310, 330 can be made of a generally flexible material becausethe stop 320 provides a measure of rigidity at least portions of thecable assembly 300. In portions where additional stiffness is desired,various thermoplastic or thermoset polymers may be used to stiffenand/or reduce the surface energy and/or to provide a smooth surface toreduce sliding friction between the outer cable section 330 and achannel.

The central cable section 310 and the outer cable section 330 can eachcontain stem tubes generally as described above with respect to FIGS.2-7. In some embodiments, the outer cable section 330 includes tensilemembers, and the central cable section 310 includes fiber optics andelectrically conductive stem tubes, or a combination of fiber opticcomponents and electrically conductive sheaths. Virtually anycombination and arrangement of stem tubes is possible. FIG. 8Billustrates a cross-sectional view of a cable assembly 300 as shown inFIG. 8A. The cable assembly 300 includes a plurality of stem tubes 350,a stop 320, and barbs 322. (The outer cable section 330 is not shown.)The stem tubes 350 can include fiber optic components, electricallyconductive components, and tensile members in any combination andarrangement. For example, a first stem tube 350 a can be an opticalfiber, a second stem tube 350 b can be an optical fiber having anelectrically conductive sheath, a third stem tube 350 c can be a tensilemember that is not necessarily electrically or optically conductive, anda fourth stem tube 350 d can be and electrically conductive tensilemember. The stem tubes 350 can be wound in a litz array to mitigate the“skin effect” that can occur when the cable assembly 300 is used totransmit high frequency, AC voltages. The stem tubes 350 can alsoinclude one or more stem tubes 350 e at a center of the cable assembly300. In some embodiments, some of the stem tubes 350 can carry opticalsignals of a first wavelength, while another group of the stem tubes 350carries optical signals of a second wavelength. For example, stem tube350 a can carry light in the visible spectrum; stem tube 350 b can carryan infrared signal; and stem tube 350 c can carry an ultraviolet signal.Other combinations are possible. The stem tubes 350 that areelectrically conductive can also have differing characteristics. Forexample, a group of stem tubes 350 can be used with a high-frequency ACvoltage and can accordingly be arranged in a litz array, while anothergroup of stem tubes 350 is used with a DC voltage, and therefore neednot be braided or woven in a litz array. The cable assembly 300 can alsoinclude bristles (not shown) similar to those shown above with referenceto FIGS. 2-7. The bristles can be positioned at a different locationalong the cable assembly 300 than the stop 320 to avoid interfering withthe stop 320.

The barbs 322 are shown in FIG. 8B at four, cardinal directions aroundthe circumference of the stop 320. In other embodiments, the barbs 322are arranged continuously around the circumference of the cable assembly300, or in a different distribution. Different applications may call formore or less force from the actuator 302 (FIG. 8A), and accordingly, thebarbs 322 can be adjusted to withstand an appropriate amount of force.

FIG. 8C illustrates another embodiment of a cable assembly 300 includinga central stem tube 360, several peripheral stem tubes 362, a stop, andbarbs 322 on the stop. The central stem tube 360 can be an opticalfiber, or include an optical fiber within a sheath. The peripheral stemtubes 362 have a non-circular cross-sectional shape. The peripheral stemtubes 362 can be electrically conductive, and they may be tensilemembers capable of withstanding a tensile load placed on the cableassembly 300 by an actuator. FIG. 8C shows six peripheral stem tubes362, but other embodiments can include more or fewer peripheral stemtubes 362. Various other configurations and cross-sectional shapes arepossible.

It will be apparent that various changes and modifications can be madewithout departing from the scope of the disclosure. For example, thenumber, layout, and materials of the stem tubes 210 may be altered toinclude alternative materials and processing means. The assembly 100 mayinclude alternative configurations than those shown and described andstill be within the spirit of the disclosure.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense as opposed to anexclusive or exhaustive sense; that is to say, in a sense of “including,but not limited to.” Words using the singular or plural number alsoinclude the plural or singular number, respectively. When the claims usethe word “or” in reference to a list of two or more items, that wordcovers all of the following interpretations of the word: any of theitems in the list, all of the items in the list, and any combination ofthe items in the list.

The various embodiments described above can be combined to providefurther embodiments. All of the U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications and non-patent publications referred to in thisspecification and/or listed in the Application Data Sheet areincorporated herein by reference, in their entirety. Aspects of thedisclosure can be modified, if necessary, to employ fuel injectors andignition devices with various configurations, and concepts of thevarious patents, applications, and publications to provide yet furtherembodiments of the disclosure.

These and other changes can be made to the disclosure in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the disclosure to thespecific embodiments disclosed in the specification and the claims, butshould be construed to include all systems and methods that operate inaccordance with the claims. Accordingly, the invention is not limited bythe disclosure, but instead its scope is to be determined broadly by thefollowing claims.

I claim:
 1. A cable assembly, comprising: a stem tube having a first endand a second end, the stem tube including an optical fiber and anelectrically conductive sheath; electrically conductive bristlesextending from the stem tube and configured to maintain the stem tube atleast generally aligned within a channel; a first electrode connected tothe first end, the first electrode being positioned near a secondelectrode and configured to deliver an ionizing voltage between thefirst and second electrodes; a sensor at the first end of the stem tubeconfigured to detect at least one of pressure, temperature, light, ormovement and to relay an associated signal along the optical fiber; anda cable actuator connected to the second end of the cable and configuredto actuate the stem tube by tensioning the stem tube.
 2. The cableassembly of claim 1 wherein the channel is within a fuel injectoradjacent to a combustion chamber, and the sensor is configured to detecta combustion event in the combustion chamber.
 3. The cable assembly ofclaim 1, further comprising a tensile member extending along the stemtube and configured to bear a tensile load caused when the cableactuator tensions the stem tube.
 4. The cable assembly of claim 1wherein the optical fiber is configured to bear a tensile load causedwhen the cable actuator actuates the fuel injector by pulling the cable.5. The cable assembly of claim 1 wherein the stem tube comprises aplurality of stem tubes arranged in a litz array, wherein the litz arrayis a braided configuration configured to deliver the voltage to theelectrode pair.
 6. The cable assembly of claim 1 wherein the bristlesare generally rigid and maintain the cable generally centered within thechannel.
 7. The cable assembly of claim 1 wherein the cable furthercomprises electrically conductive strands arranged concentrically aroundthe optical fibers and configured to deliver the voltage to theelectrode pair.
 8. The cable assembly of claim 1 wherein the voltagecomprises an AC voltage.
 9. The cable assembly of claim 1 wherein thevoltage comprises a DC voltage.
 10. The cable assembly of claim 1wherein the bristles are configured to maintain the cable at leastgenerally centered within the channel.
 11. The cable assembly of claim 1wherein the bristles are wound around the cable in a helix or a doublehelix.
 12. The cable assembly of claim 1, further comprising anelectrically conductive sleeve lining at least a portion of the channel,wherein at least a portion of the bristles are electrically conductiveand form part of an electrical path for the voltage between theelectrically conductive sleeve and the electrode pair.
 13. The cableassembly of claim 12 wherein the electrically conductive sleeve lines afirst portion of the channel but not a second portion of the channel,and wherein bristles that contact the second portion of the channel arenot electrically conductive and have low friction between the channeland the bristles.
 14. The cable assembly of claim 13 wherein the cablemoves between a first position when the valve is closed and a secondposition when the valve is open, and wherein the conductive sleevecontacts at least a portion of the electrically conductive bristles atboth the first position and the second position.
 15. The cable assemblyof claim 12, further comprising an electrical lead configured to deliverthe voltage to the electrically conductive sleeve, wherein theelectrical lead remains stationary relative to the electricallyconductive sleeve as the cable moves between the first position and thesecond position.
 16. The cable assembly of claim 1 wherein the stem tubecomprises a plurality of stem tubes arranged into a group of centralstem tubes and a group of outer stem tubes, the cable assembly furthercomprising a stop fixed to the central stem tubes and to the outer stemtubes, wherein the stop is between the central stem tubes and the outerstem tubes, and wherein the stop is configured to limit the movement ofthe cable assembly within the channel.
 17. The cable assembly of claim 1further comprising a stop fixed to the stem tube and configured toengage a shoulder that is fixed relative to the channel, wherein thestop is configured to limit a range of motion of the cable assemblywithin the channel.
 18. A fuel injector, comprising: a dielectric bodywith a channel extending between a fuel reservoir and a fuel combustionchamber; a cable assembly positioned within the channel, the cableassembly including— an optical fiber, an electrically conductive strand,and a plurality of generally rigid filaments extending radially from theoptical fiber and the electrically conductive strand and contacting thedielectric body to maintain the cable generally centered within thechannel; a valve operably coupled to the cable and positioned betweenthe channel and the fuel combustion chamber; a valve actuator connectedto the cable and configured to move the cable in the channel to actuatethe valve and permit fuel to enter the fuel combustion chamber from thechannel; a sensor positioned on the valve and configured to detect acombustion event in the fuel combustion chamber, wherein the sensor isconnected to at least one of the first and second bundles and configuredto relay a signal along the optical fibers to report the combustionevent.
 19. The fuel injector of claim 18, further comprising anelectrically conductive lining in a portion of the channel, wherein atleast a portion of the filaments are electrically conductive and contactthe electrically conductive lining.
 20. The fuel injector of claim 19,further comprising an electrical lead contacting the electricallyconductive lining, wherein the electrical lead, the electricallyconductive lining, the electrically conductive filaments, and the valveform an electrical path through which electricity is delivered to form aplasma in the channel to deliver the fuel into the fuel combustionchamber.
 21. The fuel injector of claim 18 wherein the optical fiber andthe electrically conductive strand are wound such that the filamentsform a helix around the cable.
 22. The fuel injector of claim 18 whereinat least one of the optical fiber and the conductive strand isconfigured to bear a tensile load in the cable caused by the valveactuator.
 23. The fuel injector of claim 18 wherein at least one of theoptical fiber and the conductive strand comprises a plurality of stemtubes arranged in a braided litz array.
 24. A valve actuation mechanism,comprising a valve; means for sensing at least one of heat, light,pressure, or motion, the means for sensing being positioned at thevalve; a cable connected to the valve, the cable being configured to—sense at least one of heat, pressure, and motion opposite the valve,carry an optical signal from the means from sensing to a controller, andconduct electricity along the cable; means for actuating the valve bypulling on the cable to move the valve between a closed position to anopen position; a brush bearing comprising a plurality of bristlesprotruding from the cable to maintain the cable at least generallycentered within a bore, wherein the brush bearing permits the cable tomove between the open position and the closed position within the bore.25. The valve actuation mechanism of claim 24 wherein the cablecomprises at least one optical fiber configured to— withstand tensileforces caused by the means for actuating the valve; and carry an opticalsignal from the means for sensing.
 26. The valve actuation mechanism ofclaim 24 wherein the optical fiber comprises an optical core and anelectrically conductive sheath surrounding the optical core.
 27. Thevalve actuation mechanism of claim 25 wherein the optical fiber is madeof at least one of fiber glass, polyimide, polyamide-imide, aluminumfluoride, quartz, and sapphire.
 28. The valve actuation mechanism ofclaim 24 wherein the cable comprises— an optical fiber configured tocarry the optical signal; and an electrically conductive strandconfigured to conduct electricity along the cable and to bear a tensileload caused by the means for actuating.
 29. The valve actuationmechanism of claim 24 wherein the valve comprises a valve for a fuelinjector, and the means for sensing comprises means for detecting acombustion event through the valve.
 30. The valve actuation mechanism ofclaim 24, further comprising means for biasing the valve toward at leastone of the open position and the closed position.
 31. The valveactuation mechanism of claim 24 wherein the cable comprises a pluralityof strands arranged in a litz array.
 32. The valve actuation mechanismof claim 24 wherein the cable comprises a plurality of concentric layersof strands.
 33. The valve actuation mechanism of claim 24 wherein atleast a portion of the bristles and at least a portion of the bore areelectrically conductive.
 34. The valve actuation mechanism of claim 24wherein the cable comprises at least two bundles, and the bristles ofthe brush bearing extend between the bundles.
 35. A method ofmanufacturing a litz wire, comprising: forming a litz wire from aplurality of stem tubes, the stem tubes individually including anoptical core and an electrically conductive sheath surrounding theoptical core; forming a brush bearing in the litz wire having bristlesextending transversely to the litz wire; attaching a valve to a firstend of the litz wire; attaching a sensor to the valve, wherein thesensor is coupled to the optical fibers to convey an optical signal fromthe sensor along the fibers; coupling the litz wire to a valve actuator;and positioning the litz wire in a channel of a housing with the valvebeing configured to actuate to inject a fluid from the housing when thevalve actuator actuates the valve, wherein the brush bearing isconfigured to bear the litz wire at least generally centered within thechannel.
 36. The method of claim 35 wherein forming the litz wirecomprises braiding the plurality of stem tubes, and wherein forming thebrush bearing comprises weaving the bristles within the litz wire. 37.The method of claim 35, further comprising coupling the litz wire to anionizing source and an electrode pair, wherein the ionizing power sourceis configured to deliver a voltage along the litz wire and ionize atleast a portion of the fluid.
 38. The method of claim 35 wherein formingthe brush bearing comprises forming the bristles into a helix around thelitz wire.